Table 3. Influence of IL in Estragole Isomerization Using 6/Phosphorous ligand systemsa.
| entry | ligand | IL (amount) | time | conv. (%) | sel. (%)b |
|---|---|---|---|---|---|
| 1 | P(OEt)3 | BMI·NTf2 (0.5 g) | 3 h | 83 | 98 |
| 2 | P(OEt)3 | nPr(OH)MI·NTf2 (0.5 g) | 30 min | 99 | 99 |
| 3 | P(OEt)3 | nPr(OH)MI·NTf2 (0.1 g) | 1 h | 99 | 99 |
| 4 | PPh3 | nPr(OH)MI·NTf2 (0.5 g) | 30 min | 99 | 99 |
| 5 | PPh3 | nPr(OH)MI·NTf2 (0.1 g) | 1 h | 99 | 99 |
a
Reaction conditions: estragole 2.0 mmol, estragole/6 ratio of 100, P(OEt)3 0.04 mmol, IL 0.5 g, T = 80 °C, and estragole filtered over aluminum oxide.
b
Selectivity for trans-anethole.